Monday, April 28, 2014

Synchronous Fireflies at Elkmont Tour Gatlinburg 2014

Event dates are June 4-11

Synchronous fireflies (Photinus carolinus) are one of at
least 19 species of fireflies that live in Great Smoky Mountains
National Park. They are the only species in America whose individuals
can synchronize their flashing light patterns.

Fireflies (also called lightning bugs) are beetles. They take from
one to two years to mature from larvae, but will live as adults for only
about 21 days. While in the larval stage, the insects feed on snails
and smaller insects. Once they transform into their adult form, they do
not eat. Most species produce a greenish-yellow light; one species has a bluish
light. The males fly and flash and the usually stationary females
respond with a flash. Peak flashing for synchronous fireflies in the
park is normally within a two-week period in late May to mid-June.

No one is sure why the fireflies flash
synchronously. Competition between males may be one reason: they all
want to be the first to flash. Or perhaps if the males all flash
together they have a better chance of being noticed, and the females can
make better comparisons.

The fireflies do not always flash in
unison. They may flash in waves across hillsides, and at other times
will flash randomly. Synchrony occurs in short bursts that end with
abrupt periods of darkness.

As the season begins, a few insects
start flashing, then more join the display as the days pass. They reach a
"peak" when the greatest number of insects are displaying. After peak,
the numbers gradually decline each day until the mating season is over.
Since 1993, this peak date has occurred at various times from the third
week of May to the third week in June.

During the two week long mating season,
the quality of individual nightly displays can be affected by
environmental factors. On misty, drippy evenings following rainfall, the
insects may not readily display. Cool temperatures, below 50º
Fahrenheit, will also shut down the display for the night. Moon phase
has been observed to affect the timing of nightly displays-on nights
with a bright moon, the insects may begin flashing a bit later than
usual.